It is well established that children can easily fall into a body of water such as a swimming pool or wander into the ocean and end up drowning. In the past, a parent kept track of a child by holding their hand or by tethering the child to themselves using some sort of leash, but many would view tethering as child abuse and it could be dangerous if the tether is too long allowing it to be caught, trapping the child and the parent as well in a dangerous situation.
There are different types of devices and systems that have been suggested to avoid these tragedies but they fail to alert the child's guardians early enough to make them effective. They also tend to be complicated to use or too basic to provide any value. Some systems fail to accurately alert to a water danger or water emergency, or fail to provide any advanced warning of the child's proximity to the water danger, and tend to be limited to one body of water and are not portable.
For the foregoing reasons, there remains a need for a system to alert a parent before a child enters any large body of water providing a parent an opportunity to intervene from enough notice.